RE: WRES AND OUTLIER IDENTIFICATION/EXCLUSION

From: Michael.J.Fossler@GSK.COM Subject: RE: [NMusers] WRES AND OUTLIER IDENTIFICATION/EXCLUSION Date: Tue, 26 Sep 2006 08:29:34 -0400 My personal preference is not to exclude any points based on outlier criteria. By doing so, you may be excluding important information. To take an extreme example, if you were modeling consecutive games played in the majors, would you exclude Cal Ripkin? He is clearly an outlier, and yet excluding him from the data-set would bias your model significantly. You would be trading model relevance for a better fit, which is not a good trade-off. Excluding data which are in error should be done, but those data are not outliers, they are errors. Apologies to my European colleagues for the baseball reference. Insert your favorite soccer example above (:^)) Mike ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Michael J. Fossler, Pharm. D., Ph. D., F.C.P. Director Clinical Pharmacokinetics, Modeling & Simulation GlaxoSmithKline (610) 270 - 4797 FAX: (610) 270-5598 Cell: (443) 350-1194 Michael_J_Fossler@gsk.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~